Method of and apparatus for credit verification

ABSTRACT

A credit verification system comprising a multiplicity of pointof-sale terminals and a programmed central processing unit with data storage equipment communicating with the terminals for automatically performing a credit check on the accounts corresponding to the credit cards inserted in the terminals. Each of the terminals is adapted to receive and operate with a plurality of different credit cards representing different credit card plans with the data storage equipment storing account information for each of the credit plans. After the various credit checks are performed by the central processing unit, the transaction authorization is communicated to the terminals. In certain instances, the central processing unit may refer the transaction to a video display terminal where an operator establishes voice communication with an external authorization center.

Stephenson, Jr. et al.

[451 Apr. 10, 1973 METHOD OF AND APPARATUS FOR CREDIT VERIFICATION [58] Field Inventors: Kenrick O. Stephenson, Jr., Upper Montclair, N.J.; George D. Telepko, Rydal, Pa.; C. Philip Strakosch, Tappan, N.Y.

Digital Data Systems Corporation Feb. 26, 1971 us. Cl ..340/149 A, 179/2 CA Int. Cl. ..G06k 5/00, l-IO4q 5/00 of Search ..235/6l.7 B, 61.11 A, 235/6l.11 C; 340/149 R, 149 A, 152 R; 179/2 CA References Cited UNITED STATES PATENTS 9/1969 Sallach "2 35/6111 C l/ 1971 Pomeroy ..340/ 149 A 2/1971 Presti ..340/149 A X 7/1971 Braun... ..340/l52 R 4/1971 Huber ..34 0/l52 R 3,544,769 12/1970 Hedin ..340/l49RX Primary Examiner-Donald J. Yusko Att0rneyWoodcock, Washburn, 1 Kurtz & Mackiewicz ABSTRACT A credit verification system comprising a multiplicity .Of point-of-sale terminals and a programmed central processing unit with data storage equipment communicating with the terminals for automatically performing a credit check on the accounts corresponding to the credit cards inserted in the terminals. Each of the terminals is adapted to receive and operate with a plurality of different credit cards representing different credit card plans with the data storage equipment storing account information for each of the credit plans. After the various credit checks are performed by the central processing unit, the transaction authorization is communicated to the terminals. In certain instances, the central processing unit may refer the transaction to a video display terminal where an operator establishes voice communication with an external authorization center.

14 Clains, 23 Drawing Figures TERMINAL PATENTEHAFR Toma sum 01 a; 15

CARD

TERMINAL c CARD TERMINAL CONCENTRATOR MESSAGE ASSEMBLER I AUTH BOX FILE ADD DELETE 1 BOX WARNING J FILE LIST UPDATE I/O BUFFER CENTER PROGRAM CRT H TO AUTHORlZATlON T CENTERS DATA IS RECEIVED 50 FROM A'POS DEVICE TIME LIMIT AND NO ACKNOWLEDGEMENT FROM DECLINE OR APPROVAL WAS SEND DATA TO SIGNAL CRT UNIT IND. SENT A DECLINE? N0 ACKNOWLEDG N AN APPROVAL SEND MESSAGE TO MESSAc s E QENDINO CRT IND NO ACKNOWLEDGEMENT AC 'I I IOII IEREgE ON A DECLINE v|74 BUFFER? TRANSACTION F lg. ll IDENTIFICATION OF CARD PLAN IS THE CHECK DIGIT VALID? F lg 2 IS THE ACCOUNT ON THE WARNING LIST? CHECK THE ls ADD THE 7 I ACTIVITY THE ACCOUNT NO ACCOUNT TO I FOR THE M ON THE ACTIVE THE ACTIVE PRESENCE OF FILE? FILE THIS ACCOUNT 98 PAIDIIEIII II I 3,727,186 SHEET 030F15- INVALID NUMBER BE IDENTIFIED BY THE IS THIS THE 2nd CONSECUTIVE ERROR FROM THIS BOX? SEND THE DATA TO THE SEND THE CRT FOR DATA TO THE v62 56 ESITEQ I IR VISUAL W' IDENTIFICATION THE POS.

ISSUE A RESEND TO THE BOX. THIS INITIATES A MAX.

OF 3 TRY BY THE DEVIcE TO SEND THE'DATA NEw- TRANSACTION WAS RECEIVED WITH AN OLD TRANSACTION PENDING REFERRAL IS ACKNOWLEDGEMENT PENDING? I ON THE NEW TRANS? LOG THE OLD TRANSACTION ON THE LOG TAPE I a I 7s 80 OLD TRANS- THIS INDICATES wAS SENT TO I THE IMPRINTER cRT FOR DID NOTIFUNCTION REFERRAL ON THE APPROVAL PUT THE NEW 70 SEND THE OLD TRANSACTION -IN THE BUFFER OVERLAY OLD TRANS. TO THE A EA TRANS. wITH ,cRT. OVERLAY R Y NEW I THE OLD WITH THE NEw TRANSAcTION Ob @b PATENTEU APR 0 I975 SHEET ACT I VITY BEYOND PRESCRIBED YES lo 24 HOUR LIMIT? SEND A STANDBY TO THE POS DEVICE ADDI TO THE ACTIVITY couNTER FOR THIS ACCO T UN SEND THE TRANS.

TO THE CRT FOR REFERRAL WRITE THE DATA BACK TO THE ACTIVE FILE 106 Fig. 6

ACCOUNT IS ON WARNING LIST THE ACCOUNT IS FOUND ON STATUSED ACCOUNT FILE IS THE STATUS AUTH. REFERRAL OR HOT CARD G IUF I5 IS THE CARD PLAN A SUBSCRIBER DOES THE AMOUNT EXCEED THE FLOO LIMIT I28 SEND APPROVAL TO POS DEVICE Fig.7

Fig.5

HOT CARD REFE RRAL 9O SEND THE TRANS- SEND TRANS. TO CRT INDICATING THE ACCOUNT IS ON THE HOT /94 CARD LIST TO THE CRT FOR REFERRAL SEND A STANDBY SIGNAL TO POS DEVICE RETURN TO ISSUE STANDBY TO POS DEVICE AND RETURN To PROCESS NEXT ENTRY PROCESS OTHER ENTRIES PATENTEIJ W5 3'. 727, 186

sIIEE USUF 1s REQUEST CARD PLAN EXCEEDS OR NOT ACCEPTED BY MERCHANT INPUT EXIST FOR THIS FROM CARD PLAN ZERO IND. N0

SEND M ESSAGE TO CONSOLE YES TYPEWRITER INDICATING LACK OF FLOOR LIMIT INPUT SEND A FRoM THE Pos STANDBY To THE Pos "\-'I2O DEVICE DEVICE IS IS THE ACCOUNT THIS AN FROM AN ACKNOWLEDGEMENT OUT -oF-AREA PLAN? I PUT TRANs.

DATA To THE INDICATE THE 1 LOG TAPE ouT-oF-AREA PLAN IN THE cRT MESSAGE A TEST EAcH BUFFER I66 AREA FoR A PENDING ACKNOWLEDGEMENT. TEsT IS PERFORMED ON THE TIME THEIR 26 INITIAL SIGNAL WAS sENT TO CRT FOR AUTHORIZATION THERE AN CKNOWLEDGEMENT PENDING PATENTED IPR I 0 ma SHEET ENTRY HAS THE TRANSACTION A WARNING LIST ENTRY? IS THE ACCOUNT YES BEEN RECEIVED FROM THE CRT STATUS RECOGNIZED USUF I5 TO THE CRT.

CHECK WARNING LIST FOR PRESENCE OF THE ACCOUNT THE ENTRY SEND A MESSAGE INDICATING THE ERROR COND- ON IS THE ACCOUNT ON FILE? UPDATE THE ACCT.

wITH THE NEW STATUS,

WRITE THE ACCT. BACK TO THE DRUM LOG THE TRANSACTION IS THIS A DELETE TRANSACTION? ADD THE ACCT. TO THE FILE.

WRITE THE DATE TO THE LOG TAPE YES THIS A LOG UPDATE TRANS? YES UPDATE LOG FILE wITH DATA FROM THE CRT.

\ DATA IS AN APPROVAL OR DECLINE OF A PREV. TRANS.

IS THIS TRANS. STILL IN THE POS, DEVICE? UPDATE LOG /'FILE WITH I54 REJECT ITEM.

CLEAR BUFFER INDICATE THIS CONDITION TO THE CRT UNIT PATENTE APR] 0191a SHEET 08 0F 15 VGOJQ 2 non mwm

E. E. N. C.

s EL PATENTEMPR 1 01915 3'. 727. 186

SHEET 0 9 [1F 15 M CLOCK M CLOCK PATENTED 1 01973 3. 727. 186

SHEE l 1 OF 1 5 Fig [2d DATA NEXT CH WT) REQ I K 5 37 TO ERRT 5 F +5 TO SHEET 133F- 15.3

PATENTED APR 01973 Fi .I5

PATENTEU APR 1 0 ma SHEET lSUF 15 METHOD OF AND APPARATUS FOR CREDIT VERIFICATION BACKGROUND OF THE INVENTION a forwarding address. Bankruptcy is a third category and the inability or refusal to pay incident to changes in employment, military induction, health failure and death make up the fourth category. The losses which may be attributed to the various categories represent an overwhelming dollar volume.

It therefore becomes increasingly clear that an automated system for checking credit for credit card accounts is a necessity. Slow and expensive clerical checking is completely impractical.

THE PRIOR ART Automated credit verification systems used with credit cards havebeen developed in response to this demand. One such system is the Creditmaster (TM) system which is manufactured and sold by Digital Data performs various credit checks on the account identified by the transaction terminals. Although this system has met with overwhelming commercial acceptance, it is designed and limited to a single credit checks on the accounts represented by credit cards issued by a single credit card plan or department store.

There is however a need for a system which will check the credit of accounts in various credit card plans. Bank and travel credit'card plans are a case in point. Since merchants will frequently honor more than one such credit card plan, there is a need to check the credit of credit card holder regardless of the particular credit plan. If a Creditmaster system approach were utilized to solve the problem of such a merchant, the merchant would be burdened with one point-of-sale terminal for each credit card 'plan honored with each terminal communicating with a separate central processing facility for the corresponding credit card card plan. In other words, the system performs credit the transaction amount against after the credit card initiating the credit check has been removed from the terminal and'another credit card has been inserted into the terminal initiating a subsequent credit check. Obviously, a false authorization could result.

SUMMARY OF THE INVENTION in accordance with one aspect of the invention, a system for verifying the credit of credit card accounts in a plurality of credit plans having different credit authorization requirements is provided. The system comprises a plurality of point-of-transaction terminals,

each of the terminals adapted to transmit signals representing credit card plans and account number to a central processing means. The credit checking is per- I formed by the central processing means after first identifying the appropriate account number and appropriate credit plan. The terminals and the central processing means are linked by communication means.

In accordance with another aspect of the invention, the signal transmitted to the central processing means also represents terminal data to enable the central processing meansto identify the appropriate terminal and determine if the credit authorization requirements of the identified terminal have been satisfied. After the credit check is performed, the central processing means generates signals which are transmitted to the appropriate terminal so as to authorize the transaction. In certain instances, the entire transaction may be referred to-a visual display authorization means which is attended by an operator. Additional communication means may then be provided to link the visual display with the terminals and the central processing means various creditchecks are programmed into the central processing means. For example, check digit validation may beperformed by the central processing means. Other checks involve the deterniination of extraordinary activity in the identified accountas well as acheck-of the floor limits for an identified terminal. I

In accordance with another important aspect of the invention, a buffer file is provided at the central processing means with an entry for each terminal. The buffer file includes fixed information relating to the terminal and variable information describing the input transaction. Such a file will prevent authorization of a transaction after the corresponding credit card has been removed from the transmitting terminal and plan. The impracticality of such an arrangement is apparentwhen the counterspace required for the various terminals is considered. Furthermore, great expense would be involved to the various credit plans sincev each would be required to maintain its own central processing facility.

When an authorization function has'been provided by a central processing unit in the prior art, problems have arisen in appropriately coordinating the authorization with the credit card in the terminal. In other words, the authorization from the: central processing facility might hev received at the terminal another credit card inserted.

These and other aspects of the invention are set forth in the following specification with reference to the drawings.

, BRlEF DESCRIPTION OF THE DRAWINGS FIG. 12c is a schematic diagram of the circuitry in the terminal transmit and print control section;

FIG. 12d is a schematic diagram of the circuitry in the terminal datacontrol and mechanics control section;

FIG. 13 is a perspective view of the exterior for a system terminal;

FIG. 14 is a top plan view of the interior of a system terminal;

FIG. 15 is a side elevational view of the interior of a system terminal;

FIG. 16 is a view taken along section line 16-16 of FIG. 15;

FIG. 17 is a view taken along section line 17-l7 of FIG. 15;

FIG. 18 is another view taken along section linel7- l7; and

FIG. 19 is a view taken along section line l9--19 of FIG. 17.

TABLE oF CONTENTS holders account numbers and the dollar amount of the transaction or sale on the sales draft 18 in machine readable form. Note that various kinds of credit cards 16 as represented by the letters a, b, and c are received by the terminals 10 so as to provide a credit verification system for use with various credit plans in accordance with another important aspect of the invention.

The system operation is initiated by clerks at the terminal 10. In this connection, the clerk is instructed to record all creditsales at the terminal regardless of the credit card used by the customer. A clerk uses the terminal 10 by first keying in the account number to agree with the card holders account number on the em bossed plastic credit card 16. Next, the clerk enters the amount of the sales by pressing appropriate keyboard keys. The embossed card 16 and the sales draft '18 are placed into the device and a verification button on The system will be understood from the following detailed description which has been divided into sections which, are set forth here for convenience of reference: I

1.0 The Overall System, Block Diagram, FIG. 1 2.0 On-Line System Processing, Flow Charts,

FIGS. 2-11 3.0 A'System Terminal, Block Diagram, FIG. 12

3.1 Keyboard, FIG. 12a I 3.2 Memory and Data Edit Section, FIG. 120 3.3 Memory Control Section, FIG. 12b 3.4 Transmit and Print Control Section, FIG.

12c 3.5 Communications Data Control and Mechanical Control Section, FIG. 12d 3.6 Communications Section, 3.7 The Exterior of the Terminal, FIG. 13 3.8 The Mechanical Structure of the Terminal,

FIGS. 14, 15 and 16 3.9 The Mechanical Operation of the Terminal,

FIGS. 17, 18, and 19.

Detailed Description of a Preferred Embodiment I .0 The Overall System A credit verification system for credit cards representing the preferred embodiment of the invention will first be described with reference to FIG. 1. As shown there, the system comprises the following three functional aspects: transaction entry at point-of-sale terminals 10; a referral function through a video display terminal 12 with voice communication to credit authorization centers external to the system; and a programmed computer function centered at a general purpose computer 14 for system control, normal authorization and record keeping.

Each of the tenninals 10 comprises a counter-top data entry device and printer capable of imprinting the data that is embossed on the card holder's card 16 on a transaction or sales draft 18. In addition, the terminal the keyboard is depressed. The message which is generated at the terminal 10 is now transmitted to the computer 14 through communication means including a concentrator 20, high speed telephone lines 22, and a message assembler 24. It should be appreciated that the terminals 10 by merchant numbers associated with the 1 terminals and a number for the telephone nearest each of the terminals 10. In addition, the box file 26 includes an accumulator for storing data representing the floor I limit for each card plan, a continuing count of the number of approved transactions, and a totaling of the dollar amount of approved transactions at the particular terminal.

Since the service charge for credit verification may very well be distributed on a merchant by merchant basis, the box file 26 providesa particularly convenient means of merchant billing. In this connection, it will be noted that the total volume of approved transaction is contained in the box tile as well as the number of approved transactions thereby providing a basis for usage billing. In addition, the information in the box file 26 may be utilized to generate I/O (input/output) buffers for an I/O buffer file 28 of the general purpose computer 14. This is a CPU core resident file having a number of entries corresponding to the number of terminals 10 which contains fixed information relating to the merchants having terminals and variable information regarding the input transaction. The very important functions served by the buffer file is to insure that transaction authorization from the computer 14 to the particular transmitting terminal is received at the time the correct charge card 16 and sales draft 18 are in the terminal 10. For example, if credit verification were requested with respect to a charge card 16-0, it is very important that the particular transaction be authorized at the time charge card l6-c is stillin the terminal 10 and not after the charge card 16-h in the next transaction has been inserted into the terminal 10.

The data stored in the [/0 buffer file 28 includes identification of the particular terminal l0, floor limit codes indicating the floor limit for each plan (a, b, or c), input messages such as the authorization request from a particular terminal 10, and internal control fields. In addition, the number of the telephone nearest the particular terminal is stored in the buffer file 28. Upon finding the buffer with a pending request, this transaction can be sent to the operator of the visual display means 12 for disposition and a new request may be received by the buffer. The buffer always contains the transaction present in the terminal 10.

The non-fixed field, and the flag fields of the I/O buffer file 28 are used for dynamic storage of information while the on-line program is in operation. The fixed fields, the box number, floor limit codes and the telephone number are inserted during the generate l/O buffer phase when the on-line program commences.

A warning file 30 which may be a drum resident index sequential file is used to store the account number and a flag of those accounts for which a pickup card" or a do not authorize order has been sent out by the card issuing plan. The flag indicates the type of condition that will cause referral to the video display 12.

In order to increase access speed from the computer ,14 to the warning list file 30 and save storage space, the file may be split in two. The first file will contain all account numbers less than 16 characters in length, each of which will require four words of storage. The second file will contain all of the account numbers greater than characters in length, each of which will require 5 words for storage. The data stored in the warning file 30 includes account numbers and flags with corresponding referral codes.

Since the status of certain accounts may change during the on-line program of the computer 14, a dynamic warning file 32 is provided which is also drum resident accessed by the computer 14. This file is created randomly during the on-line program by new adds sent from the operator at the visual display means 12. The file is also accessed randomly from the computer 14. As in the case of the warning list file 30, the dynamic warning list file 32 includes data representing the account number and a flag including a referral code.

In certain instances, it will be necessary for the operator of the visual display means 12 to communicate with another authorization center before approving or disapproving of a transaction. It is therefore important to maintain a drum resident authorization center file 34 which may be accessed by the computer 14. The contents of the file include identification numbers for the authorization centers and corresponding telephone numbers. Finally, a log file 36 is provided to record transactions processed during the on-line program, to update the box file usage and volume counters in the box file update, to provide input data for the box file update. For this purpose, the log file 36 includes data representing counter device identification, the sequence number of a transaction from the terminal 10, an account number, and the amount of the transaction. In addition, the data represents an authorization number assigned by the computer 14 or the authorization center and an action code identifying the type of entry in the log file. The log file may be stored on tape. I

The source of information in the various files will now be described briefly. As mentioned previously, the dynamic warning list file 32 is generated by update information obtained from the operators visual display means 12. As also mentioned previously, the dynamic warning list file 32 permits the maintenance of an upto-date warning list. Note that the warning list file 30 is not updated during the on-line program. (Broken lines indicates off-line processing.) Instead, the warning list file 30 is generated by a box file warning list update program 38 in response to data from the log file 36, add/delete cards 40 and the box file 26 data. The box file 26 is also updated with the program 38. Similarly, the authorization center file 34 is maintained by means of an off-line authorization center program 42.

When a sales clerk at one of the terminals 10 seeks authorization of a transaction arising out of the use of a particular credit card, a message generated at the terminal 10 is transmitted to the computer 14. The message comprises a start message symbol, a card code identifying a type of card used (credit plan), an account number, a box or terminal number, a sequence number indicating the transaction count for the terminal 10, the amount of the transaction, and an end message symbol. All of this is transmitted to the computer 14.

The on-line program for the computer 14 then accesses the on-line warning list file 30 and the box file 26 to determine the disposition of the request. If it is determined that the request can be approved immediately, that is if the account is not on the warning list and the amount is below the merchant floor limit, an approval message is returned to the transmitting terminal and terminal automatically approves the transaction. The tape log file is then updated with this transaction and the system waits for the next request. However, in certain instances when a referral is needed, a message is sent to the visual display means 12 which may be a uniscope CRT with a code describing the action taken on the account.

The request to the visual display operator may be for anyone of the following reasons:

1. to request authorization of an over-the-limit transaction;

2. notifying the operator of the use of an invalid card;

3. request for retransmission of a message from the counter device; or

4. inform the operator of hardware problems.

The authorization request message which is received by the visual display operator includes a referral code indicating one of the foregoing reasons for the request and a telephone number of an authorization center from the authorization center tile 34 or a point of sale device telephone number from the box file 26. The operator of the visual display then communicates with the particular terminal 10 or the dynamic warning list file 32. The communicated message to they terminal 10 will include the authorization number assigned by that authorization center or in the event the transaction is rejected, a reason for rejection. In the latter case, the account number is also included in the message.

2.0 On-Line System Processing The following account conditions are checked by the system after a transaction is entered at a terminal 10:

l. validity of data entered; I

2. status of the account, i.e., on the warning list; and

3. the amount of the transaction is under the floor limit. In addition, the system provides the following verifications which are made on the transaction:

I. data received, account, box number, sequence,

and amount, are verified for numeric content;

2. the issuing plan is identified and the appropriate check digit validation is performed;

3. the status list is scanned for the presence of the account;

4. the card-usage file is checked for over activity;

5. the card plan is checked against the merchant plans accepted and the amount is checked against the floor limit;

6. an approval signal is generated at the computer and transmitted to the terminal;.and

7. acknowledgement from the terminal is transmitted to the computer 14 prior to the logging of the transaction. The data of the transaction is now written in the log file 36 and the card-usage file stored in the computer 14 is updated. If the account was not previously in the-cardusage file 14, the account is added. If the card is already in the card-usage file, the number of transactions on this account are updated. The foregoing will now be described more specifically with reference to the flow charts of FIGS. 2-1 1.

As shown in FIG. 2, the data is received at the central processing unit 14 (50). A check is made to see if the message content is complete and numeric (52). If the answer to this question is in the negative, one of two potential conditions exists. First, the data received is garbled and the box number is invalid. Second, clerical mistakes have been made in the entry of the data at the terminal 10.

As shown in FIG. 3, a check is then made to see if the box number of the terminal can be identified by the central processing unit 14 (54). If the number cannot be identified by the central processing unit 14, the transaction is not processable by the on-line system and the data as it is received is sent to the visual display for operator identification (56). If the visual display operator can identify the terminal 10, voice contact may be initiated with an appropriate request for reinitiating the transaction authorization request.

If the data received includes invalid data in the amount or account field of the message, a resend signal may be transmitted from the central processing unit 14 to the terminal 10. If only one error has been received from the terminal 10 (58), a resend signal is transmitted to the terminal (60). In the event that two consecutive errors have been received from terminal 10, the data is set to the visual display 12 initiating voice contact between the visual display operator and the terminal (62). I

Referring again to FIG. 2, if the message content is complete and numeric, a determination is made as to whether a message transmitted from the requesting terminal is pending in the buffer file 28 (64). If a new transaction was received with an old transaction pending as shown in FIG. 4, a determination is made as to whether acknowledgement is pending (66). If an acknowledgement is not pending, this means that the old transaction was sent to the visual display 12 for referral (68) and the new transaction is overlaid with the old transaction (70). If an acknowledgement is pending for the old transaction, a determination is made as to whether the sequence number increased on the new transaction (74). If the sequence number did I not increase, this indicates that the carriage at the terminal 10 did not function on the approval from the central processing unit 14 and the old transaction is then sent to the visual display 12 and overlaid with the new transaction (78). If the sequence number did increase, the old transaction is logged in the log file 36 (80) and the new transaction is placed in the [/0 buffer 28 (82).

The transaction is now ready for identification of the account number and the issuing credit card plan (71) as shown in FIG. 2. Once the account and issuing plan have been identified, the transaction is ready for a number of checks. First, a check digit validation (72) is performed. If the check digit test fails, a resend signal is returned to the terminal 10 (60). After two resends have been sent to the terminal 10, the transaction is sent to a visual display 12.

The next check determines whether the account is on the warning list (84) as shown in FIG. 2. If the account is on the warning list (86) as shown in FIG. 5, the

' status of the account must be determined (88). If the statused as a hot card", a message is transmitted to the visual display 12 indicating the account is on the hot card list (94). Again, a standby signal is transmitted to the terminal 10 indicating the central processing unit 14 is ready to process the next transaction entry for that particular terminal (96).

. In the event that the account is statused for referral to the visual display, the visual display operator will call the authorization center of the appropriate card plan. Upon receipt of authorization, the operator enters the transaction through the visual display 12 with a decline or an authorization numberindicating approval. This data is then transmitted to the terminal 10. When an authorization is transmitted, a transaction is entered in the log file 36 after acknowledgement from the-terminal 10 to the CPU 14.

If the account is not on the warning list, a check in the activityfile is made for the presence of the account (98) as shown in FIG. 2. If the account is on the active file (100), a determination must be made whether the activity is beyond the prescribed 24 hour limit (102) as shown in FIG. 6. If the activity is not beyond this limit, a one is added to the activity counter for this account (I04), and data is written back to the active file (106). If the activity is beyond the prescribed 24 hourlimit, a standby signal is transmitted to the termianl 10 (108) and the transaction is referred to the visual display 12 (110). v v

If the activity on the account is not beyond prescribed 24 hour limit, a determination is now made regarding the acceptability of card plan by the merchant having the requesting terminal (112) as shown in FIG. 7. If the card plan. is accepted by the merchant, a determination is made as to whether or not the transaction authorization requirements for a substantial numberof cards in a given credit card plan for 

1. A system for verifying the credit of credit card holders prior to transactions: a plurality of credit card sets corresponding to a plurality of credit card plans, each credit card in each of said sets carrying indicia identifying a credit card plan and an account number in said credit card plan; a plurality of point-of-transaction terminals, each of said terminals adapted to generate signals representing transaction data including the account number, the dollar amount of the transaction and the credit card plan; a communication link between each of said terminals and a central location for transmitting said signals representing the transaction data to said central location; a central processing means located at said central location and connected to said communication link, said central processing means receiving the transmitted signals representing the transaction data, said central processing means including: a means for storing transaction authorization requirements for each credit card plan, said requirements differing for different credit card plans and being the same for a substantial number of credit cards in a given credit card plan for various transactions at a given terminal; a means for retrieving the stored transaction authorization requirements of a transmitted credit card plan; and a means for determining if the transmitted dollar amount satisfies said stored authorization requirements for said transmitted credit card plan.
 2. A system of claim 1 wherein said central processing means generates signals representing transaction authorization and refusal and said communication link transmits said transaction authorization and refusal signals to the appropriate terminal.
 3. A system of claim 2 including visual display authorization means adapted to be attended by an operator; and an additional communication link between said visual display means and said central processing means for transmitting operator authorization of a transaction.
 4. The system of claim 1 wherein said central processing means further comprises: a means for storing the status of account numbers in each of said credit card plans; and a means for retrieving the stored status of a transmitted account number.
 5. The system of claim 4 wherein each of said terminals is adapted to generate signals identifying said terminals, said stored transaction requirements for a given credit card plan varying as a function of the particular terminal involved in each transaction.
 6. The system of claim 1 wherein said central processing means comprises means for storing a log of each of said transactions occurring at each of said terminals.
 7. The system of claim 2 wherein said central processing means including buffer storage means for each of said terminals for indicating the pendency of transactions at the terminals.
 8. The system of claim 1 wherein each of said terminals comprises means for applying machine readable transaction data to a transaction draft.
 9. The system of claim 8 wherein each of said terminal means comprises means for applying transaction authorization data from said central processing means to said transaction draft.
 10. A method of checking credit of cRedit card holders belonging to different credit card plans by utilizing a single remote terminal located at each remote transaction point and a central processing means comprising a digital computer and digital storage means located at a central location, said method comprising the steps of: storing transaction authorization requirements for each of said credit card plans in said digital storage means, said transaction authorization requirements varying as a function of the particular credit card plan involved in the transaction; generating signals at said remote terminals representing transaction data, said transaction data including the credit card plan involved in a transaction and the dollar amount of the transaction; transmitting said signals representing said transaction data from said remote terminals to said central processing means; retrieving from said digital storage means transaction authorization requirements for each transmitted credit card plan; and determining with said digital computer if the transmitted transaction data satisfies the retrieved transaction authorization requirements.
 11. A method of claim 31 wherein said transaction authorization requirements for a given credit card plan vary as a function of the particular terminal involved in each transaction, said method further including the steps of: generating signals at said terminals representing transaction data including the remote terminal involved in each transaction; transmitting from said terminals said signals representing the terminal involved in each transaction to said central location so as to permit a determination by said digital computer of whether the transmitted dollar amount of the transaction satisfies the transaction authorization requirements for the particular terminal and particular credit card plan involved in each transaction.
 12. The method of claim 11 further comprising the steps of: storing the status of accounts in each of said credit plans at said digital storage means, generating signals representing transaction data including the account number involved in each transaction at said remote terminals, transmitting said signals representing said transaction data including each said account number to said central location, determining with said digital computer the status of each transmitted account number.
 13. The method of claim 10 including the step of performing a check-digit validation on the identified account for the transmitted credit card plan at said central processing means.
 14. The method of claim 13 including the step of determining extraordinary activity for the identified account at said central processing means. 